Over the years I have created sayings which I post in my classroom to motivate my students. This can be printed on letter size paper or enlarged for bigger paper. I laminate them and use them over and over.
"Too often the emphasis in math classes is on memorizing tricks and finding the answer fast. THis reinforces the wrong habits of Mind. Spending time wresting & puzzling, trying ideas, making mistakes and then trying different ideas is where real learning takes place."